diff --git a/apparmor.d/tunables/extend b/apparmor.d/tunables/extend
index 7dd32b0e..5f4c09cf 100644
--- a/apparmor.d/tunables/extend
+++ b/apparmor.d/tunables/extend
@@ -9,6 +9,8 @@
 # Universally unique identifier
 @{uuid}=[0-9a-f]*-[0-9a-f]*-[0-9a-f]*-[0-9a-f]*-[0-9a-f]*
 
+# Hexadecimal
+@{hex}=[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]
 
 # @{MOUNTDIRS} is a space-separated list of where user mount directories
 # are stored, for programs that must enumerate all mount directories on a